When we upgraded our Angular app to the latest version. We noticed everything worked with version 4.2.3 and Typescript 2.4.
After we reinstalled all the nom packages the Angular version was upgraded to 4.2.4, because we had in our package.json ‘^4.2.3’ for Angular packages.
When we package everything and republished the app to the page, we got errors, huh!!!!
After some search I found it has to do with the combination of Typescript and Angular version. After I set Typescript fixed to version 2.3.4 everything works fine againby